test(#4513): migrate git plumbing batch to named timeout constants

Batch 2 of the ad hoc timeout literal migration (epic #4445). Replaces
every bare numeric timeout/timeoutMs object-literal property in
tests/git-base-branch.test.cjs, tests/commit-files-pathspec.test.cjs,
and tests/git-fixture.test.cjs with a named constant, per
eslint-rules/no-adhoc-timeout-literal.cjs. Removes the 3 files from
the rule's allowlist.

This batch introduces a violation shape not seen in Batch 1: several
sites are pinned-value test assertions verifying the EXACT timeout
production code hardcodes (not bounds on this suite's own subprocess
calls). Named as four separate constants even where values coincide,
so the tests keep catching independent production drift instead of
silently tolerating it. No src/bin file touched, no numeric value
changed anywhere -- verified site-by-site by two independent isolated
review passes.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/commit-files-pathspec.test.cjs

@@ -22,7 +22,7 @@ const { createTempGitProject, cleanup, runGsdTools } = require('./helpers.cjs');
 const { execFileSync } = require('node:child_process');
 const { gitOrThrow } = require('./helpers/git-fixture.cjs');
 // #3145: class-norm timeout, not a per-suite value — see helpers/timeouts.cjs.
-const { GIT_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
+const { GIT_TIMEOUT_MS, PROBE_TIMEOUT_MS } = require('./helpers/timeouts.cjs');
 const {
   bareCommandName, tokenize, shellDashCPayloads, commentPortion,
   ISSUE_REF_RE, declarationReason, isDeclared, isUntrackedDeclaration,
@@ -433,6 +433,16 @@ describe('commit --files: pathspec honors declared scope (#2112)', () => {
 // shared DEFAULT_GIT_TIMEOUT_MS norm.
 const STAGING_GIT_TIMEOUT_MS = 5000;
 
+/**
+ * `commitWithFailingAdd`/`subrepoCommitWithFailingAdd` below spawn
+ * `process.execPath -e <script>` where the script mocks `execGit` in-process
+ * (no real git subprocess runs) and calls `cmdCommit`/`cmdCommitToSubrepo`.
+ * Not the same class as `PROBE_TIMEOUT_MS` (15000ms) below — kept at its
+ * pre-existing, more generous value rather than lowered without a bench
+ * citation proving 15000ms is safe for this harness.
+ */
+const MOCKED_GIT_SPAWN_TIMEOUT_MS = 30000;
+
 const LIB = path.join(__dirname, '..', 'gsd-core', 'bin', 'lib');
 
 /**
@@ -488,7 +498,7 @@ cmdCommit(${JSON.stringify(cwd)}, 'docs: map existing codebase', ${JSON.stringif
 
   const run = spawnSync(process.execPath, ['-e', script], {
     encoding: 'utf8',
-    timeout: 30000,
+    timeout: MOCKED_GIT_SPAWN_TIMEOUT_MS,
     killSignal: 'SIGKILL',
     env: { ...process.env, GSD_TEST_MODE: '1' },
   });
@@ -548,7 +558,7 @@ cmdCommitToSubrepo(${JSON.stringify(cwd)}, 'feat: subrepo change', ${JSON.string
 `;
   const run = spawnSync(process.execPath, ['-e', script], {
     encoding: 'utf8',
-    timeout: 30000,
+    timeout: MOCKED_GIT_SPAWN_TIMEOUT_MS,
     killSignal: 'SIGKILL',
     env: { ...process.env, GSD_TEST_MODE: '1' },
   });
@@ -3195,7 +3205,7 @@ projection.execGit = (args, opts) => {
 };
 cmdCommit(${JSON.stringify(cwd)}, 'docs: probe', ${JSON.stringify(files)}, false, false, false);
 `;
-    const run = spawnSync(process.execPath, ['-e', script], { encoding: 'utf-8', timeout: 15_000 });
+    const run = spawnSync(process.execPath, ['-e', script], { encoding: 'utf-8', timeout: PROBE_TIMEOUT_MS });
     if (run.status !== 0 && !run.stdout) {
       throw new Error(`probe crashed: ${run.stderr}`);
     }
@@ -3207,9 +3217,16 @@ cmdCommit(${JSON.stringify(cwd)}, 'docs: probe', ${JSON.stringify(files)}, false
     tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-3886-'));
     fs.mkdirSync(path.join(tmpDir, '.planning'), { recursive: true });
     fs.writeFileSync(path.join(tmpDir, '.planning', 'STATE.md'), '# State\n');
-    execFileSync('git', ['init', '-b', 'main'], { cwd: tmpDir, timeout: 15_000 });
-    execFileSync('git', ['config', 'user.email', 't@example.com'], { cwd: tmpDir, timeout: 15_000 });
-    execFileSync('git', ['config', 'user.name', 'T'], { cwd: tmpDir, timeout: 15_000 });
+    // `GIT_TIMEOUT_MS` (15000ms, "plumbing READS") rather than the heavier
+    // `GIT_FIXTURE_TIMEOUT_MS` (60000ms, "fixture CONSTRUCTION calls —
+    // init/config/add/commit") that helpers/git-fixture.cjs's own docstring
+    // says this exact call shape belongs to. Not reclassified: doing so would
+    // RAISE this site's bound 15000ms -> 60000ms with no bench citation
+    // proving the smaller value is unsafe here — out of scope for a
+    // rename-only migration. Flagged, not silently resolved either way.
+    execFileSync('git', ['init', '-b', 'main'], { cwd: tmpDir, timeout: GIT_TIMEOUT_MS });
+    execFileSync('git', ['config', 'user.email', 't@example.com'], { cwd: tmpDir, timeout: GIT_TIMEOUT_MS });
+    execFileSync('git', ['config', 'user.name', 'T'], { cwd: tmpDir, timeout: GIT_TIMEOUT_MS });
   });
   afterEach(() => cleanup(tmpDir));
 
@@ -3247,7 +3264,7 @@ projection.execGit = (args, opts) => {
 };
 cmdCommit(${JSON.stringify(tmpDir)}, 'docs: probe', ['.planning/STATE.md'], false, false, false);
 `;
-    const run = spawnSync(process.execPath, ['-e', script], { encoding: 'utf-8', timeout: 15_000 });
+    const run = spawnSync(process.execPath, ['-e', script], { encoding: 'utf-8', timeout: PROBE_TIMEOUT_MS });
     const result = JSON.parse(run.stdout);
     assert.equal(result.reason, 'commit_timeout', 'the timeout gate must win over the nothing-to-commit text in partial output');
     assert.equal(result.timed_out, true);
@@ -3268,7 +3285,7 @@ projection.execGit = (args, opts) => {
 };
 cmdCommit(${JSON.stringify(tmpDir)}, 'docs: probe', ['.planning/STATE.md'], false, false, false);
 `;
-    const run = spawnSync(process.execPath, ['-e', script], { encoding: 'utf-8', timeout: 15_000 });
+    const run = spawnSync(process.execPath, ['-e', script], { encoding: 'utf-8', timeout: PROBE_TIMEOUT_MS });
     const result = JSON.parse(run.stdout);
     assert.equal(result.committed, false);
     assert.equal(result.reason, 'commit_failed');